Modular leads

ABSTRACT

A leads frame for use with pile driving machines including a plurality of stackable modular elements, the front and rear chords of which are provided with interengaging cooperative locking portions which upon assembly provide a rigid structure of the leads frame.

[11] 3,747,689 1451 July 24, 1973 United States Patent 1 1 Frederick S N m T A w .L P P A R mo 8 T s m 2 WP MN 0 E m F e M 2 6 9 l 2 l 211 Appl. 110.; 142,173

1,284,691 1/1962 France 182/178 Primary Examiner-James A. Leppink Attorney-Edwin E. Greigg and Everett G. Clements 57 ABSTRACT A leads frame for use with pile driving machines includ- Int. E02d 7/00 [58] Field of Search 173/90, 42, 43, 134, 173/124; 52/120, 645, 646, 648, 655; 188/67;

ing a plurality of stackable modular elements, the front [56] Refer Cit d and rear chords of which are provided with interengag- UNITED STATES PATENTS ing cooperative locking portions which upon assembly 8/193!" Ydrk provide a rigid structure of the leads frame.

1,195,976 8/1916 Chesebro.....

PATENTEDJIJLPMQB INVENTOR FREDERICK This invention relates to the construction of the leads frame used for pile driving, and more specifically to a modular leads frame construction allowing for vertical extensions thereof for driving piles of various lengths. Such an arrangement thus reduces the weight of the leads frame required and the ease of handling by allowing the use of the minimum size frame for a given pile.

BACKGROUND OF THE INVENTION There has long been a need for on-site tailoring of the leads frame lengths to fit the requirements of specific pile driving jobs. In addition, there are several modes of operation of pile driving which required different leads frame assemblies or constructions to be effective. Normally, there are three modes of driving referred to as fixed extended leads, underhung fixed leads, and free swinging leads from a crane line with the bottom of the lead stabbed into the ground. Each of these modes requires the addition of or re-arrangement of lead sections and although thishas notbeen done before it is desirable that this be accomplished as quickly as possible.

OBJECT, SUMMARY AND ADVANTAGES OF THE INVENTION Accordingly, it is the principal object of this invention to provide a rigid light weight modular lead section that may be varied in an assembly to form a lead of suitable length whichvwill fit the mode of driving dictated by the terrain or foundation excavation.

Another object of this invention is to provide a split guide rail that gives two additional linear surfaces that can be used for recoil braking of the hammer apart from the three normal surfaces upon which the hammer is guided. This braking surface is to be used by a pneumatic brake mounted on the hammer to stop or retard hammer recoil caused by the upward travel of the ram or piston, thus eliminating the need for weighting of the hammer and thereby reducing the weight that the crane must lift when rigged as a pile driving unit.

Still another object of this invention is to provide braking surfaces for recoil braking of the hammer which can be kept free of grease, oil and scuffing, to provide uniformity of friction which cannot be achieved when the guide rails are used for a braking surface It is still another object of this invention to provide a modular leads frame which is self-aligning and can be assembled rapidly with only moderate skill.

The invention will be better understood, as well as further objects and advantages of the invention will become more apparent, from the ensuing detailed specification of a preferred, although exemplary,embodiment of the invention taken in conjunction with the drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational view showingthe modular lead sections assembled and attached to the boom tip of a commercial crane;

FIG. 2 shows a plan view and a partial cross sectional view of a typical leads frame module looking down at an assembled joint; and

FIG. 3 shows in side elevation a typical joint disclosing the clamping and alignment features in cross section.

DESCRIPTION OF THE EMBODIMENT Turning now to FIG. 1, there is shown a typical modular leads frame mounted on a crane made up of a sheave head 40, the top taper portion 41, a removable intermediate section 42 and bottom section 43 with bottom brace 47 connection. Beneath the top taper is secured an auxiliary sheave 44 and the customary boom tip adapters 45.

The length of the leads may be varied according to desire by separating the leads frame at' joint 46, for example, by adding or subtracting intermediate sections such as typified at 42. A swinging leads may be made by removing the sheave head 40 as well as the boom tip connection and the auxiliary sheave, and thereafter attaching the crane line directly to the top of taper section 41. At that time, it is also necessary to add stabbing points 82 (see FIG. 1) to the bottom of bottom section 43. In this mode of operation it is: not contemplated to use the bottom brace indicated at 47 this being disclosed in my copending patent application filed concurrently herewith. The underhung mode can be achieved by removing the boom tip connection as well as the auxiliary sheave 44 and the: sheave head 40, and thereafter attaching the boom tip to the top taper section 41 by the tip adapters 45. The boom in this case must be extended with the bottom. brace still remaining assembled and attached to bottom section 47. This illustrates the use of modular leads from sections in adapting the leads frame for various modes of operation and usages.

Referring now to FIG. 2, there is shown in this view which is taken looking down into an assembly joint a cross section of the C-shaped modular section of the leads frame wherein although the longitudinal mem-' bets are illustrated as being tubular, they may be of any desired configuration, square or rectangular or channels in cross section. The rear chords 50 and 51 are square tubular sections which are maintained in spaced relation by a rectangular brace 52 welded therebetween. Although it is not shown in the plan view of FIG. 2, it will be understood that a series of these braces 52 hold alignment over the entire length of the modular section. Welded to and extending forwardly from the rear chord are parallel spaced hollow arms 53-53, the terminal comprising the front chords of the section 42 in the hollow vertical members, portion 54 of which abuts the vertically perforated block 55, the diametrically opposite side of said block being secured to the hollow front chord element, said element forming one member of the front chord 56 of the modular section denoted as 42 in FIG. 1.

The front chord member 56 serves as a guide for the hammer, this element being more clearly shown in phantom lines in the plan view of FIG. 2. Rearwardly of the hammer guide and secured adjacent to one side of the terminal armis another longitudinally extending tubular element which functions as a braking surface member 57 for the hammer. The block 55 is arranged to receive the tie bolt 58 for assembly of one module section to an adjacent section as is more clearly shown in FIG. 33.

Referring now to FIG. 3, there is shown a block 59 which is provided with a collar 60 that acts as an alig nment guide and is arranged to mate with a cavity 24 which is formed in the lower surface of the matching block 55 of the adjacent section, thus providing positive alignment between multiple sections.

With reference being made at this time to the rear chords of the adjacently disposed modular sections, the bottom of the rear chords have welded thereinto filler blocks 61 these being threaded parallel to the axis of the leads. At the top of an adjacent assembly of the rear chords perforated blocks 62 are arranged to receive a bolt 63, the shank thereof being splined at 64 and captured by a hexagon-shaped collar 65, all of which is held in place by a snap ring 66 and adapted to prevent the bolt from falling down into the rear chords.

Thus, in view of the foregoing description it will now be apparent that when two modular sections are to be assembled bolt 63 is threaded into the block 61 by turning collar 65 until the lower surface of the upper rear chord section and the upper surface of collar 65 are tightly in contact which, at the same time, brings the upper surface of the lower rear chord section and the lower surface of the collar 65 tightly into contact. The rear chords and the thickness of the collar 65 are sized so that when they are brought together tightly as described, surfaces 70'and 71 of the rails 56 and 57 respectively, are substantially in tight contact. The upper and lower surfaces are machined perpendicular to the axis of the leads so that the rails will achieve perfect straightness when modular sections are bolted together. After the rear chords are assembled, as explained, the high strength tie bolt 58 is positioned in the aligned perforations in blocks 55 and 59, and a nut 61' is threaded onto the bolt 58 and drawn up tight, thus clamping the ends of the rail surfaces together.

At high hammer rates on double acting steam or airpowered hammers or double acting diesel hammers the hammer ram itself being very heavy, tends to remain stationary when it is forced downward, thus imparting a recoil to the hammer housing and tending to lift the housing or cylinder, thereby negating or reducing the energy in the hammer blow. The methods of overcoming this is to increase the mass of the housing by loading it with weight, or to use a portion of the steam or air pressure to apply brake shoes to the guide rails, thus effectively locking the hammer housing to the leads frame. Since the guide rails are heavily greased and their coefficient of friction is low, it necessarily requires heavy braking pressures to lock the housing securely against the recoil.

Referring again to FIG. 2, there is disclosed in outline phantom a hammer showing the engagement of the forward hammer guides 76 and the rearward hammer guides 77 fitting slidably against surfaces 78 and 79, respectively. The opposed surfaces 80-80 of the guide rails 56 and 57 form braking surfaces against which oppositely offstanding brake shoes carried by laterally disposed braking drive means 81-81 can expand and 7 thereby control movement of the hammer 75.

It should be clear that the methods of construction described in the specification present but one practical approach to achieving the desired results and they should not limit the scope or intent of the present invention.

What is claimed is:

1. In a pile driving machine having a boom associated with a leads frame the combination comprising a plurality of stackable modular elements having front and rear chords with each of said respective chords being of tubular construction, the front and back chords each terminating in interengaging cooperative portions including locking means at the tops and bottoms thereof, rail means spaced from the front chords, said rail means and said front chords further having opposed surfaces, said front chords providing guideways for a hammer and the rail means forming braking surfaces for the hammer.

2. In a pile driving machine as claimed in claim 1, wherein the hammer includes a portion that glides between the rail and the front chord.

3. In a pile driving machine as claimed in claim 1, wherein at least one of the locking means for said front and rear chords is disposed in alignment with one of the chords.

4. In a pile driving machine as claimed in claim 1, wherein at least one of the locking means for said stackable modular elements is interposed between said confronting surfaces of the front and rear guideways.

5. In a pile driving machine as claimed in claim 1, wherein said locking means is disposed laterally of said braking means.

6. In a pile driving machine as claimed in claim 1, wherein at least one of said locking means includes a portion carried by one of the chords. 

1. In a pile driving machine having a boom associated with a leads frame the combination comprising a plurality of stackable modular elements having front and rear chords with each of said respective chords being of tubular construction, the front and back chords each terminating in interengaging cooperative portions including locking means at the tops and bottoms thereof, rail means spaced from the front chords, said rail means and said front chords further having opposed surfaces, said front chords providing guideways for a hammer and the rail means forming braking surfaces for the hammer.
 2. In a pile driving machine as claimed in claim 1, wherein the hammer includes a portion that glides between the rail and the front chord.
 3. In a pile driving machine as claimed in claim 1, wherein at least one of the locking means for said front and rear chords is disposed in alignment with one of the chords.
 4. In a pile driving machine as claimed in claim 1, wherein at least one of the locking means for said stackable modular elements is interposed between said confronting surfaces of the front and rear guideways.
 5. In a pile driving machine as claimed in claim 1, wherein said locking means is disposed laterally of said braking means.
 6. In a pile driving machine as claimed in claim 1, wherein at least one of said locking means includes a portion carried by one of the chords. 